Modular multilevel cascade converter based statcom for reactive power compensation

The design and implementation of multilevel voltage source converter based static synchronous compensator (STATCOM) is dealt with in MATLAB Simulink. The objective of this study is to stabilize the voltage by compensating the reactive power in the system. Cascaded Multilevel Converter (CMC) based Static Compensator (STATCOM) is used for reactive power control. A cascaded multilevel converter is a three phase VSC which comprises of three single phases and each phase consists of H-bridges connected in series. Each single phase H-bridge converter has two arms consisting of two pairs of GTO and diode connected in anti-parallel. Each H-bridge has its own capacitor, acting as a voltage source. Individual capacitors of same capacitance are selected to meet the economic and harmonic criteria. This work proposes the enhancement of power transfer capability and maintaining unity power factor. Relative Harmonic analysis is also discussed based on the total harmonic distortion (THD) calculations. MATLAB/SIMULINK tool is used for evaluating the performance of the proposed control scheme.